That is my understanding (from a newspaper article some years ago) except that is not approval that is required, you just need to notify the relevent people - presumably the registrar, so when someone else finds bones in future years they will know why the bones are there. I think it is discouraged though.Apparently it is legal to bury someone (if they are dead, etc.) in your garden... you "just" have to get the EHO's approval, and I guess it would get logged on your deeds - or the Land Registry's modern equivalent.
I suspect it might have a severe negative effect on an ordinary house's value, but on a huge country estate? less so.